Landing gear usually supports an aircraft when it is not flying, allowing it to take off, land, refuel, be maintained, and taxi. Typical landing gear includes wheels, skids, skis, floats or a combination of these and other elements depending on both the surface and on whether the aircraft operates vertically (e.g., vertical takeoff and landing “VTOL”) or is able to taxi along the surface. Landing gear may be fixed in a single position or capable of retraction and deployment, as required. Faster aircraft usually have a retractable undercarriage (e.g., the landing gear of the aircraft is housed within wheel wells during flight), which folds away during flight to reduce air resistance or drag. Conventional takeoff and landing (“CTOL”) aircraft typically have wheels to facilitate rolling during takeoff and landing.
However, typical landing gear supports the aircraft in only a single orientation or with slight adjustments in height and/or angle. For example, landing gear skids (e.g., on a rotorcraft or fixed-wing aircraft) or landing gear wheels (e.g., on a fixed-wing aircraft) are designed to be used only when the aircraft is in a specific orientation. If an aircraft is intended to be positioned or stored in multiple positions, such as an aircraft that takes off using a runway but lands vertically (e.g., in a tail-sitter orientation), multiple sets of landing gear are needed.
Additionally, transitioning the aircraft between sets of landing gear can be difficult. For example, large external support equipment (e.g., jacks or overhead cranes) is often required to reposition the aircraft. While this sort of equipment is traditionally available in a maintenance hangar or other support facility, it is not likely to be available when the aircraft is deployed in the field.
Accordingly, those skilled in the art continue with research and development efforts in the field of aircraft landing gear.